Article
Population genetic structure and phenotypic diversity of Aspidodera raillieti (Nematoda: Heterakoidea), a parasite of Didelphini marsupials in Brazil’s South and Southeast Atlantic Forest
Registro en:
VARELLA, Karina et al. Population genetic structure and phenotypic diversity of Aspidodera raillieti (Nematoda: Heterakoidea), a parasite of Didelphini marsupials in Brazil’s South and Southeast Atlantic Forest. Parasites & Vectors, v. 15, 203, p. 1 - 19, 2022.
1756-3305
10.1186/s13071-022-05288-6
Autor
Varella, Karina
Vilela, Roberto do Val
Gentile, Rosana
Cardoso, Thiago dos Santos
Costa Neto, Sócrates Fraga da
Maldonado Junior, Arnaldo
Resumen
Background: The population genetics of parasites may be influenced by host specificity, life cycle, host geographical
range, evolutionary history, and host population structure. The nematode Aspidodera raillieti infects different marsupial
and rodent hosts in the Nearctic and Neotropical regions, implying a gene flow among populations. However, niche
diversification of the main hosts of A. raillieti in superimposed areas may provide conditions for population genetic
structuring within this parasite species. We examined the genetic structuring of A. raillieti infecting three marsupial
species co-occurring along the South and Southeast Brazilian Atlantic Forest, a hotspot of biodiversity.
Methods: We employed morphometric analyses and partial mitochondrial cytochrome c oxidase I gene sequences
(MT-CO1) to characterize populations via phylogenetic and phylogeographic analyses.
Results: Among 175 A. raillieti specimens recovered from the marsupial hosts Didelphis aurita, D. albiventris, and Philander
quica, we identified 99 MT-CO1 haplotypes forming four haplogroups and four clades in networks and phylogenetic
trees, respectively. Clades I and II encompassed parasites of D. albiventris from the South region, clade III comprised
parasites of D. aurita from the South and Southeast regions, and clade IV encompassed parasites of D. aurita
and D. albiventris from the South and Southeast regions and parasites of P. quica from the South region. High genetic
differentiation between clades, with a high fixation index and greater genetic variation in the analysis of molecular
variance (AMOVA), indicated low gene flow between clades. Haplotypes shared among host species revealed a lack
of host specificity. A significant correlation in the Mantel test suggested parasite isolation by distance, while there
was no evidence of geographical structure between populations. Negative neutrality test values for clades III and IV
suggested recent population expansion. Morphometric differentiation between A. raillieti specimens recovered from
different host species, as well as from different localities, was more evident in males.